Johnny Ringo, a notorious gunslinger, is hired as the sheriff of Velardi, Arizona, a wide-open frontier town. His first act as the Velardi's lawman is to hire the town drunk, Case Thomas, as his deputy. In his sober moments, Case is quite a gunsmith. He gives Johnny his latest creation - a seven-shooter - based on a design by the French gunsmith LeMat. Johnny hopes the seventh shot, a .410 gauge shotgun shell, will make the difference when he tries to run a crooked saloon owner and his henchmen out of town.
A carnival whose primary attraction is young sharpshooter Kid Adonis arrives in town. Max Healey wants to make the big-time by adding to Adonis' reputation as the man who killed Johnny Ringo. Adonis believes Ringo killed his father and wants vengeance. To make sure the young gunfighter wins, Healey plans to shoot Ringo from ambush before he can get off a shot at Adonis.
Virgil Kincaid, the owner of a hardscrabble ranch, is accused of murdering Lorna Parrott. Her six-year-old son identifies Kincaid as the killer but, during Kincaid's subsequent trial, identifies a different man. The jury finds Kincaid not guilty, but the Velardi townspeople hound the rancher, killing his stock and destroying his water barrels despite Ringo's efforts to shield him from their wrath.
Cully kills a drunken rancher who threatened him in a saloon and is stricken with remorse. Rather than face the man's three brothers who ride into Velardi demanding revenge, Cully plans to slip out of town leaving Ringo to confront the men alone.
Ringo and Cully join a pair of guards from Yuma prison searching for three escaped convicts. The lawmen quickly discover that the sadistic guards would prefer to kill the escapees then return them to state custody.
Jessie Mead rides into town and begs Johnny to put him in jail, going so far as to break a storefront window to provide an excuse. Ringo soon learns why Mead wants to be locked up - a posse of bounty hunters demands custody of the prisoner who's wanted dead or alive. Mead begs Johnny to turn him over to the U.S. Marshal, but the posse won't wait and whip the townsmen into a lynch mob. While the mob attacks the jail, the posse reveals their true nature by robbing the bank while Ringo and Cully protect their prisoner.
Cully and Ringo stumbles across an old army stagecoach hidden in an abandoned mine with a skeleton inside. After the lawmen drag the coach into town, men with no apparent connection to one another are found dead, one after the other. Ringo attempts to determine if the murders are connected to the abandoned coach or just coincidence.
During a devastating heat wave, a rain maker dressed in Biblical robes comes to Velardi and guarantees to deliver rivers of water. Ringo doesn't trust the man and Cully recognizes the man's carny pitch, but the desperate townspeople's put their faith in the bearded stranger - who is really the front man for a sinister plot.
Cyrus Hampton, a rich old man dying of an incurable disease, arrives in Velarde with a wild tiger. He plans to release the animal in a remote canyon and then hunt him down. Johnny refuses to grant him permission fearing the big cat will kill livestock or a cowboy rounding up strays. Hampton's assistant ignores the warning and releases the cat and Ringo's fears come true when a cattleman is found severely mauled by the beast.
A middle-aged saloon singer, determined to leave her abusive boyfriend, shoots him in her hotel room, then flees to Velardi. Cully sees her perform and is promptly smitten. Their romance quickly develops and appears to be headed towards the altar until the ex-boyfriend, a notorious gunslinger now recovered from his wound, traces the chanteuse to Ringo's town.
Johnny investigates Josie Wilkins' report that her father was murdered, but can't find a body nor any evidence to support her claim. Laura Thomas believes the young girl's story, and when Josie is abducted, Ringo comes to same conclusion.